I'll go for Company B.

Experience

For me, it is always exciting to watch a new company grow, and to be part of it, is special. You will get to experience walking with a company from the starting line and who knows where it will lead you to. Adventure and experience of life we're talking about here.

Stability

No business is moving up straight ahead smoothly without bumpy roads. They will always be ups and downs whether the business is new or old. The cooperation of the team behind the business is what decides whether the business will fail or not. By the way, a huge debt is scary. It will affect not just the upper chairs but the whole team.

Salary

To offer such salary as a new company is wise. They are new. The financial needed to be distributed wisely. Too much spending will end with debts. I'm pretty sure once the company reaches certain amounts of income, they will give a raise to their faithful employee. To earn it, it is up to ourselves. To perform well or not.

Working hours

It is shameful for a company to have their employee working overtime and not paying for their extra time working. This is abuse. A good company who appreciates their employee will not abuse their employee. We deserve to get paid for the extra hours we put in. To have 2 days off a week is a dream! More time to yourself for your well-being.

Seems to me, Company B is an obvious winner here. But this is only from my point of view, what really matters is your intuition. If you feel good about it, go for it!